Pick one instead of summing the results for replicated table DML.

Replicated table DML should change the same number of rows on all
partitions. Instead of summing the fragment responses from all partitions
followed by a division by the number of partitions, just pick one result and
return that to the client.
Remove replicated table DML result manipulation code from ProcedureRunner.
Skip dummy dependency results in the MpTransactionState.
Should send dummy dependency result for sysproc fragments on joining node, just
like for normal fragments.
Print stack trace when join snaphost request fails.
Remove redundant code and fix comment per Paul's review feedback.
Add test dummy fragment response to TestMpTransactionState.
Merge pull request #437 from VoltDB/dummy-frag-resp-fix

Fix dummy fragment response handling at the MPI